1. Field of the Invention
The present invention relates to an ophthalmologic apparatus for obtaining information inherent in an eye of a patient, such as information relating to eye refractive power, eye fundus image, and volume of eye fundus blood flow.
2. Related Background Art
In this type of an ophthalmologic apparatus, before an examination, it is necessary to perform positioning (alignment) of an examination unit to an eye of a person to be examined (patient). This alignment is performed as follows. An operator observes an anterior eye part image of a patient displayed on a display unit, and operates an operation device to rough align an examination unit with an eye. After a cornea reflected image or a pupil image due to an index light flux projected to an cornea of the eye is displayed on the display unit, the operator operates the operation device such that the cornea reflected image or the pupil image is aligned with a mark for alignment displayed around an optical axis, whereby exact alignment is performed. In this ophthalmologic apparatus, an acceptable range with respect to alignment between a standard position of the eye and an optical axis of the examination unit is related to an acceptable degree of deviation in a measurement value due to change in a position of the examination unit, whereby an alignment acceptable range, that is, a measurement acceptable area is determined.
Recently, a method for performing automatic alignment of the examination unit to be actuated by an actuator has been proposed. In this method, a reflected index image from the eye is detected photoelectrically, and the actuator is controlled so as to align an optical axis of the examination unit with the detected reflected index image. Here, there are a method for controlling the actuator continuously after the standard position of the eye enters the measurement acceptable area, a method for stopping control of the actuator when the standard position of the eye enters the measurement acceptable area and restarting control of the actuator when the standard position of the eye is apart from the measurement acceptable area, and the like. However, in the former method, even if the apparatus is in the state where a measurement value is obtained with a high precision, the actuator may be repeatedly controlled more than necessary. This prevents rapid measurement. On the other hand, in the latter method, when the standard position of the eye is located in an end of the measurement acceptable area and thus control of the actuator is stopped, the standard position of the eye may be apart from the measurement acceptable area in accordance with slight movement of the eye. This prevents stable measurement.
Here, although a degree is different depending on personal equation or disease factor, it is known that a vertex of the cornea is eccentric to the center of the pupil in most of the human eyes. Thus, when exact alignment of the apparatus and the eye is performed to the center of the index image, the pupil is eccentric to a light ring, whereby a light flux necessary for measurement may be shaded by the pupil. This prevents stable measurement.
Commonly, a radius of the pupil in the eye of the human becomes larger or smaller by accommodation of eye function. Thus, it is required that an operator is in practice with respect to alignment between the pupil and the apparatus examination unit. Also, in the apparatus for automatic alignment, since complicated processing is necessary to detect the center of the pupil photoelectrically, it takes a long time, whereby preventing the rapidity of measurement.
The present invention is started from the above attention. One object of the present invention is to provide an ophthalmologic apparatus in which stable measurement can be performed rapidly. Another object of the present invention is to provide an ophthalmologic apparatus in which simplification and miniaturization can be attained.
To attain the above object, according to one aspect of the present invention, there is provided an ophthalmologic apparatus comprising:
a measuring system for measuring inherent information of an eye;
a detecting system for detecting a standard position of the eye;
an actuator for actuating an optical system including the measuring system and the detecting system; and
a controller for dividing a processing procedure of alignment between the standard position of the eye and the measuring system in accordance with each of a plurality of areas, and changing a control method for at least one of the measuring system and the actuator in accordance with an area in which the standard position is located.
In the aspect of the invention, there may be provided an ophthalmologic apparatus, further comprising an light source for measurement and index projection commonly, and an optical system for performing both pickup of an index image and observation of the eye.
In the aspect of the invention, there may be provided an ophthalmologic apparatus, wherein the controller controls to perform measurement by the measuring system plural times.
In the aspect of the invention, there may be provided an ophthalmologic apparatus, wherein the plurality of areas have a first area which is a measurement acceptable area of a relative position between the standard position and the measuring system, a second area which is within the first area and is smaller than the first area, and a third area which is outside the first and second areas, and
the controller has a first step of determining that the standard position is within which of the first, second and third areas, a second step of controlling the actuator so as to enter the standard position into the second area, and a third step of allowing measurement, and performs the second and third steps when the standard position is within the first area in the first step, performs the third step when the standard position is within the second area in the first step, and performs the second step when the standard position is within the third area in the first step.
In the aspect of the invention, there may be provided an ophthalmologic apparatus, wherein the detecting system has a system for projecting an index light flux for alignment and dividing the index light flux reflected from the eye into a plurality of light flux.
In the aspect of the invention, there may be provided an ophthalmologic apparatus, further comprising a display for displaying the eye with the plurality of areas.
In the aspect of the invention, there is provided an ophthalmologic apparatus, wherein the controller controls to start measurement automatically when the standard position of the eye is within the processing procedure.
According to other aspect of the present invention, there is provided an ophthalmologic apparatus comprising:
a measuring system for measuring inherent information of an eye;
an index system for projecting an index light flux onto a cornea of the eye;
an image pickup device for picking an anterior eye part of the eye together with an index image of an index light flux reflected from the cornea;
a display for displaying an anterior eye part image picked by the image pickup device together with the index image;
an operation device for allowing an operator to operate; and
a controller for detecting a position of the index image in accordance with operation by the operation device, and performing control to display an alignment mark representing a position of the index image around the index image on the display.
In the aspect of the invention, there may be provided an ophthalmologic apparatus, further comprising an indicator for indicating to the operator whether the index image is within an area represented by the alignment mark or not.
In the other aspect of the invention, there may be provided an ophthalmologic apparatus, wherein the controller determines whether the index image is within an area represented by the alignment mark or not, and controls to automatically repeat measurement executed by the measuring system predetermined times when the index image is within the area.
In the other aspect of the invention, there may be provided an ophthalmologic apparatus, wherein the controller determines whether the index image is within an area represented by the alignment mark or not, and controls to automatically stop measurement executed by the measuring system when the index image is not within the area.
In the other aspect of the invention, there may be provided an ophthalmologic apparatus, wherein after the measurement is stopped, the controller determines whether the index image is within the area represented by the alignment mark or not, and controls to automatically restart the measurement when the index image is within the area.
According to other aspect of the present invention, there is provided an ophthalmologic apparatus comprising:
a measuring system for measuring inherent information of an eye;
an index system for projecting an index light flux onto a cornea of the eye;
a first detecting system for detecting a position of a pupil of the eye;
a second detecting system for detecting a position of an index image in accordance with a reflected light flux from the cornea by a light flux projected from the index system;
an actuator for actuating a unit including the measuring system, the index system, the first detecting system and the second detecting system; and
a controller for performing a first step of controlling the actuator so as to align an optical axis of the measuring system with the position of the center of the pupil detected by the first detecting system, a second step of determining an area of a predetermined range including the position of the index image as a center detected by the second detecting system, approximately simultaneous with completion of the first step, and a third step of controlling the actuator so as to enter the index image into the area.
In the other aspect of the invention, there may be provided an ophthalmologic apparatus further comprising an image pickup device for picking an anterior eye part of the eye and a display for displaying the anterior eye part image, wherein the area determined in the second step is displayed on the display.
In the other aspect of the invention, there is provided an ophthalmologic apparatus further comprising a light source commonly used for the index system and the measuring system.
In the other aspect of the invention, there may be provided an ophthalmologic apparatus further comprising an image pickup device commonly used for the first and second detecting systems.
In the other aspect of the invention, there may be provided an ophthalmologic apparatus, wherein the controller controls so as to project the index light flux into the eye by the index system after the first step is performed.
In the other aspect of the invention, there may be provided an ophthalmologic apparatus, wherein the second detecting system includes an aperture having a plurality of holes in a plane approximately vertical to the optical axis.
According to other aspect of the present invention there is provided an ophthalmologic apparatus comprising:
a measuring system for measuring inherent information of an eye;
an index system for projecting an index light flux onto a cornea of the eye;
a first detecting system for detecting a position of a pupil of the eye;
a second detecting system for detecting a position of an index image in accordance with a reflected light flux from the cornea by a light flux projected from the index system;
an actuator for actuating a unit including the measuring system, the index system, the first detecting system and the second detecting system; and
a controller for performing a first step of controlling the actuator so as to align an optical axis of the measuring system with the position of the center of the pupil detected by the first detecting system, a second step of, approximately simultaneous with completion of the first step, obtaining a position of a vertex of the cornea from the position of the index image detected by the second detecting system and determining an area of a predetermined range including the position of the vertex of the cornea as a center, and a third step of controlling the actuator so as to enter the vertex of the cornea into the area.
In the other aspect of the invention, there may be provided an ophthalmologic apparatus further comprising an image pickup device for picking an anterior eye part image of the eye and a display for displaying the anterior eye part image, wherein the area determined in the second step is displayed on the display.
In the other aspect of the invention, there may be provided an ophthalmologic apparatus further comprising a light source commonly used for the index system and the measuring system.
In the other aspect of the invention, there may be provided an ophthalmologic apparatus further comprising an image pickup device commonly used for the first and second detecting systems.
In the other aspect of the invention, there may be provided an ophthalmologic apparatus, wherein the controller controls so as to project the index light flux into the eye by the index system after the first step is performed.
In the other aspect of the invention, there may be provided an ophthalmologic apparatus, wherein the second detecting system includes an aperture having a plurality of holes in a plane approximately vertical to the optical axis.
Further objects of the present invention and embodiments thereof are clear in explanation of the embodiments below.